Prior-art of related stereoscopic projectors (which provides stereoscopy with static and moving bar grid barriers) creates psuedoscopic and stereoscopic viewing zones which are an inseparable bi-product of said barriers. Furthermore, psuedoscopy occurs in these presentations when the left eye receives the right eye image and while the right eye receives the image intended for the left eye.
The term psuedoscopy refers to an inverse stereo presentation whereby the background objects are perceived to be in the foreground and the foreground objects are perceived in said background, resulting in a reversal of normal depth perceived.
Common seating practices in moving barrier grid systems are designed to place the observer's chair where the appropriate stereoscopic zones are located and avoid altogether the psuedoscopic viewing zones.
IVES U.S. Pat. No. 725,567 illustrates a stereoscopic presentation with viewing limitations, whereby the stereoscopic picture requires the observer to place the left and right eye in the appropriate predetermined area or zone and must restrict head movement horizontally; otherwise psuedoscopy occurs. It is geometrically impossible to produce a vertical static barrier grid of one set bar width which satisfies multiple observers at different viewing distances and locations simultaneously.
The double-slotted shutter of MATTHEWS (U.S. Pat. No. 2,401,173) depends solely on a baffle viewing screen to effect a limited stereoscopic presentation which provides a few useful rows of spectator seats.
The invention of SAVOYE (U.S. Pat. No. 2,421,393) illustrates the necessary parallel alignment of the cylinder grid bars with the audience viewing plane to provide even stereoscopic distribution horizontally. To effect a vertical seating plane arrangement would not be possible with the invention as depicted.
The improvement in U.S. Pat. No. 2,441,674 by SAVOYE utilizes an inclined frustral cone to effect an inclined viewing plane which provides stereoscopic viewing with a selective radial seating arrangement. This invention, as depicted, cannot provide stereoscopy with a seating arrangement on a flat horizontal plane.
HESS's invention (British Pat. No. 13,034) is a lenticular screen comprising vertical cylindrical lenses. Although this invention allows greater image illumination, stereoscopic and psuedoscopic viewing zones are produced in the volumetric audience space. This system possesses stereo projection characteristics which are similar to SAVOYE, et al.
Establishing a stereoscopic viewing environment at home on the parlor floor with inventions of prior art may prove to be difficult and particularly inconvenient since psuedoscopic and stereoscopic viewing zones are present. The observers have no freedom or choice of seating arrangement when they must visually avoid psuedoscopic viewing zones, therefore elimination of said zones is desirable.
In addition, a recent rediscovery of a seemingly new 3-D volumetric display has been publicly disclosed. This 3-D presentation utilizes light emitting diode arrays that are affixed to a flat two dimensional surface which spins on a vertical axis. A computer activates certain light emitting diodes during a 180 degrees rotational interval of the diode viewing surface wherein points of light are emitted in a spacial volume contained by the spinning screen's outer perimeter to obtain a seemingly solid image of geometric objects. The volumetric display as stated cannot portray a geometric object against a flat background, nor can it present a greater impression of visual depth by geometric objects situated beyond the display's spinning perimeter; instead it requires 180 degrees of rotation to construct a perceptual impression of solidity. This particular display system is a depth limited display.